Necticut



( No Model.) 5 T. W. WELSH. PRESSURE GAGE.

No. 552,653. Patented Jan. 7, 1-896.

WITNESSES: \NVENTDB ATTORNEY AN DREW EGNMIAM PPIOTOUTHQWASHIN GT9". DC

llNiTEn STATES PATENT QEEICE.

THOMAS W. \VELSH, OF YVILMERDING, PENNSYLVANIA, ASSIGNOR TO THE ASHCROFT MANUFACTURING COMPANITOF BRIDGEPORT, CON- NE CTICUT.

PRESSURE-GAG E.

SPECIFICATION forming part of Letters Patent No. 552,653, dated January '7, 1896.

Application filed April 17, 1395- To all wiwm it may concern:

Be it known that I, THOMAS W. \VELSH, a citizen of the United States, residing in \Vilmerding, county of Allegheny, and State of Pennsylvania, have invented a new and usef ul Improvement in Pressure-Gages, of which the following is a specification.

This invention relates to that variety of pressure-gages in which a toothed sector-arm is employed that is pivoted at its lower end, and meshes at its upper end with a pinion,the shaft of which carries the index-hand, the said arm being connected bya link and lever to the expansion-tube or pressure device of the gage, so as to transmit the motion of said device to the index-hand. In such gages, as far as I am aware, the teeth on the sector-arm have been located upon its peripheral arcsurface and have engaged the pinion on the under side of the latter. When such gages are used upon locomotives, where the jar or vibration of the parts is excessive, the gradual wear upon the bearings of the sector-arm causes it to sink by gravity so that the meshing of its teeth with those of the pinion becomes imperfeet, and consequent defective indication results. In such gages, also, a sudden and considerable change in the pressure (as of the air in air-brake mechanism) is liable to cause the sector-arm to swing so far as to disengage it from the pinionpvhen the gage becomes worthless until a proper adjustment of the sectorarm with relation to the pinion has been effected again.

The objects of the invention are so to combine the sector-arm with the pinion that any lowering of the former by wear will cause its teeth to come into more intimate contact with the pinion, so that correct indication will be preserved, and by locating the pinion within the boundary of the skeleton sector-arm to enable the diverging arms of the sector to act as stops to prevent the sector from disengagement with the pinion, as hereinafter set forth.

In the accompanying drawing a front view of a pressure-gage embodying the improvement is shown, the dial and registering-hand Serial No, 646,001. (No model.)

being removed and the pinion-shaft and sector-arm shaft being shown in transverse section.

A indicates the body or frame of the gage.

B B are expansion-tubes of the Bourdon type. C is the hollow standard with which said tubes are connected. 0 c are plates secured to said standard and projecting upwardly therefrom, in which plates the shaft (Z of the sector-arm D and the shaft 6 of the pinion E have their bearings. F is the lever and G G the links which connect the lever with said arm, a screw g fastening the latter link to the arm, and H is the retractile spring, one end of which is secured in a stationary position, while the other end is attached to the shaft 6, as usual.

As shown in the drawing, the arm .D is of skeleton form and has its shaft d located at its lower end. The teeth (1 011 the arm project downwardly from the inner are surface of the arm and engage the pinion upon the upper sideof the latter. Any wear upon the shaft (1 or its bearings, and consequent lowering by gravity of the arm D, therefore, will bring the teeth cl into more intimate contact with those on the pinion and insure a continued perfect indication. It will be seen, also, that the pinion E is located within the boundary of the sector D, so that the diverging arms 61 of the latter will act as steps against the pinion to prevent a disengagement of the sec tor and pinion under sudden and considerable changes in pressure. Preferably the arms 01 are cut away at d? or bowed out at such points to allow of the desired movements of the sector without increasing the length of its arc portion.

What I claim as my invention, and desire to secure by Letters Patent, is-

1. I11 a pressure gage having an expansion tube or device connected with a sector arm which is geared with an index pinion, said sector arm being pivoted below said index pinion, to obtain a longer link connection with the expansion tube, and constructed with its gear teeth arranged on its inner are surface and meshing With the teeth on the upper side of the index pinion so that Wear upon the pivoted parts Will maintain the gear teeth in eonstant close contact substantially as described.

2. The combination with the index-hand pinion, of the sector-arm inelosing the pinion and meshing with the upper surface of the latter, and having its side-arms cut away or bowed, at d substantially as and for the purpose specified.

THOMAS \V. VELSII. \Vitnesses:

L. E. LOVE, 1-1. H. WELSH, Jr. 

